Metal turning lathe



(No Model.)

J. R. BACK.

METAL TURNING LATHE.

No. 341,207. Patented May 4, 1886'.

' a metal-turning lathe embodying my inveir UNiTED STATES PATENT OFFICE.

JOHN 1%. BACK, OF WORCESTER, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TOFREDERICK E. REED, OF SAME PLACE.

METAL-TURNING LATH E.

SEECIFICATION forming part of Letters Patent No. 341,207, dated May 4,1886.

Application filed Deccmber14, 1885. Serial No. 185,572. (No model.)

To all whom, it may concern:

Be it known that I, JOHN R. BACK, a citizen of the United States,residing at \Vorces ter, in the county of Worcester and State of 5Massachusetts, have invented a new and useful Improvement inMetal-Turning Lathes, of which the following is a specification,containing a full, clear, and exact description of the same, accompaniedby drawings representing tion, and in which- Figure 1 shows an endelevation. Fig. 2 is a sectional view of a portion of the mechanism fordriving the fced-shaft. Fig. 3. is a top view of a portion of themechanism for driving the feed-shaft, and Fig. 4 is a detached view ofthe slotted arm for holding the auxiliary pinion and di'ivingpulley.

Similar letters refer to similar parts in the several views. I

Myinvention relates to the feeding mechanism of a metal-turning lathe;and it consists in the addition of a driving-pulley to the intermediategear usually'employed in driving the leading-screw, from'which a rotarymotion is given the feed-shaft, also, in a gear and driving-pulleydriven by the intermediate gear, by which a quicker motion is given tothe feedshaft, and in devices for holding the go driving-pulleys,whereby a change of gears f may be made and the speed of the feed-shaftvaried.

A denotes the bed of the machine; B, the head-stock; C, the apron.

E is agear upon aspindle, E, driven by the live-spindle F by gearswithin the head-stock, and not shown.

G is a gear on the leading-screw, and H H are steps of a cone-pulley onthe l'eedshaft. 40 The feedshal't and the leading-screw are both held inhearings in front of the bed A, and not shown. A slotted lever, I,turning on the leading-screw as a pivot, carries the intermediate gear,J, which is brought into contact with the gear (l by adjustment in theslot a, and held in contact with the driving-gear E by the bolt Z1 inthe concentric slot 0.

Changes may be made in the relative sizes of the driving-gear E or thedriven gear G, and the speed of the leading-screw varied relatively tothe speed of the live-spindle.

This method of rotating the leading-screw is common in its essentialfeatures to all screw-cutting lathes. The relative positions of theseveral parts are, however, varied by different makers, in some casesthe leadingscrew being placed upon the rear side of the bed, with thefeed-shaft upon the front side, requiring a different arrangement of theseveral parts than that shownin the accompany- 6o ing drawings. All ofthem, however, employ an intermediate gear adjustable in its position,

to allow the size of both the gears E and G to be changed. I

Although in y present invention relates only to the devices for rotatingthe feed-shaft, the mechanism relating to the rotation of theleading-screw has been described, as a portion of it is employed in theoperation of the parts forming the subject of my invention. A usualmethod of rotating the feed-shaft has been to place on the spindle E acone-pulley, from which power is imparted to the cone-pulley H H on thefeed-shaft. This allows the speed of the feed-shaft to be varied only bythe steps 7 5 of the cone-pulleys. The intermediate'gear, J, runs looseon a sleeve, (1, held in the slot a of the lever I by a bolt, 0, whichclamps the lever I between the shoulder d and the head of the bolt, andfrom the sleeve cl depends an arm, 8c

having a slot, 9, in which the sleeve his similarly held by a bolt, t.Upon the sleeve h the belt-pulley K rotates, carrying upon its hub apinion, L, meshing with the intermediate gear,

J, and driving the pulley K by a spline,j. The nuts 7c and It" on thebolts 0 and 2' press against the ends of the sleeves (Z and h, and arelarge enough to hold the pulleys K and gear J in position. on theirrespective sleeves, where they run loose between the nuts k L and theshoulders H.

The speed of the belt pulley K may, be changed by changing the size ofone or both of the gears E and L, the vibrating lever I permitting theintermediate J to be kept in 5 mesh, and the radial slot g allowing theposition of the gear L to be varied.

To the side or hub of the intermediate J, as may be most convenient, Iattach a belt-palley, M. The pulley K is in alignment with too the stepH and the pulley M with the step H of the cone-pulley on the feed-shaft.

For work requiring a very slow speed of the l shaft and a geanwheelattached thereto, said cutting-tool I drive the feed-shaft by the step Hand the pulley M, which has a very slow speed as driven by the largegear .I and the pinion E. Thegear J'being adjustable in position permitsthe driving-pinion E to be varied in size and a variation of speed ofthe cutting-tool to be secured.

For work requiring a very quick speed of the cutting-tool I drive thefeed-shaft by the step H and pulley K, which, by the arrangement ofgearing, has a speed much faster than the pulley M, a change in the sizeof both E and L allowing a wide range in variation of speed of thecutting-to0l. n 7

As the pulleys M and K turn in opposite directions it will be necessaryto employ an open belt with one and a crossed belt with the other, inorder to rotate the feed-shaft in the feeding motion of thecutting-tool.

the same direction.

When the tool is fed by the leadingscrew, as in screw-cutting,thedriving-belt is disconnected from the pulley upon the feed-shaft, andthe intermediate gear, J, made to engage the gears E and G,theadjustment of the sleeve (1 in the slot a carrying with it the arm f.

The lever I and intermediate J, as concerned in the rotation of thefeed-shaft, are entirely independent of the gear G on the leadingscrew,but the lever I is made to turn on the leading-screw in thepresentinstance, in order to allow the intermediate to be brought intomesh with both gears E and G; but it will readily be seen that in casethe lathe is not a screw-cntting lathe and the cutting-tool onlyrequired to be fed by the rotation of the feedshaft, the leading screwwould be entirely omitted, and the lever I might be pivoted at anyconvenient point on the bed of the lathe.

In case the lathe is intended only for such work as requires a very slowfeed, the auxiliary pi-nion L and its belt-pulley K may be omitted andthe pulley M alone used, a great variation in the feed being readilysecured by varying the size of the driving-gear E; hence my presentinvention is specially adapted to those lathes known as screweuttinglathes, as in such lathes a large variety in sizes of gears are usuallyfurnished in order to vary the speed of the leading-screw.

For the purposes ofordinary lathes the beltpulley K and also theauxiliary pinion and pulley, as shown and herein described, arenecessary in order to secure a wider range in The scope ofmy inventionis not limited, however, to the employment of both, as one may beomitted in case the character of the work does not require it.

WVhat I claim as my invention, and desire to secure by Letters Patent,is--' 1. Thecombination, with the feed-shaft of a metal-turning lathe, abelt-pulley on the feedshaft, and a driving gear-wheel rotated by thelive-spindle of the lathe, of a belt-pulley in alignment'with the pulleyon the feed pulley and attached gear-wheel being adjustable in theirposition relatively to said driving gear-wheel, whereby a change in thesize of the driving'gea-r may be made, as described, and for the purposeset forth.

2. In a metalturning lathe, the combina tion, with the live-spindle andfeed-shaft of the lathe, of mechanism for conveying rotary motion fromthe live-spindle to the feed-shaft, said mechanism consisting of apulley on the feed-shaft, a gear driven by the live-spindle, and a gearmeshing therein and a pulley at tached thereto, said pulley and gearbeing carried on a lever pivoted to the bed of the lathe and held in anydesired position to engage said driving-gear, as described, and for tarymotion from the live-spindle to the feed a shaft, said mechanismconsisting of a train of gears connected with and driven by thelivespindle of the lathe, two or more of the gears in said train beingof varying size, and consequently of varying speed, and belt-pulleys attached thereto, each in alignment with a pulley onthe feed-shaft, asdescribed, and for the purpose set forth.

4. In a metal-turning lathe, the combination, with afeed-shaft having abelt-pulley at tached, a gear driven by the live-spindle, and a gearheld by and carried on an arm pivoted on the lathe, so as to beadjustable in position, of a pinion in mesh with said adjustable gear,and a belt-pulley attached to said pinion and in alignment with thebelt-pulley on the feedshaft, as described.

5. In a metal-turning lathe, the combination of a feed-shaft having abelt-pulley at tached thereto, a gear driven by the live-spindle, a gearin mesh therewith and forming an intermediate gear, a pinion in meshwith said intermediate, and a beltpulley attached to said pinion and inalignment with the beltpulley on the feed-shaft, and said pinion and itsattached belt-pulley being adjustable in position relatively to saidintermediate, so as to allow the size of said pinion to bevari'ed, asdescribed, and for the purpose set forth.

6. The combination, with the intermediate gear, of a screw-cuttinglathe, said intermediate gear being connected with and driven by thelive-spindle, and being held in a slotted lever pivoted concentricallywith the leadingscrew, of a belt-pulley attached to said intermediategear, and a pinion meshing with said intermediate gear, and abelt-pulley attached thereto, and a feedshaft with an attachedbelt-pulley in alignment with the pulleys on said gears, as described.

JOHN R. BACK.

Witnesses:

RUEUs BENNETT FOWLER, H. M. FOWLER.

ICC

